Bilayer Graphene - WSe2 Resonant Tunneling Heterostructures With Large Current Densities

ORAL

Abstract

Two-dimensional (2D) materials offer an exciting avenue to explore novel electronic devices and properties, and can be easily stacked to create designer heterostructures. We present here a study of resonant tunneling heterostructures consisting of two rotationally aligned bilayer graphene electrodes separated by a bilayer WSe2 tunnel barrier. Rotational alignment of the graphene bilayers aligns their respective band structures in momentum-space, which allows for momentum and energy conserving tunneling between the two layers. This behavior is manifested through a pronounced resonance peak in the interlayer current-voltage characteristic, and gate-tunable negative differential resistance. The studied samples show current densities exceeding 60 μA/μm2 and peak-to-valley ratios over 5 at room temperature. Theoretical calculations using a Lorentzian spectral function for the 2D quasiparticle states match closely with the experimental data. In-plane magnetotunneling measurements show a splitting of the resonance peak and suppression of the conductance, consistent with momentum conserving tunneling.

–

Presenters

  • Gregory Burg

    The University of Texas at Austin, Department of Electrical and Computer Engineering, The University of Texas at Austin, Electrical and Computer Engineering, The University of Texas at Austin

Authors

  • Gregory Burg

    The University of Texas at Austin, Department of Electrical and Computer Engineering, The University of Texas at Austin, Electrical and Computer Engineering, The University of Texas at Austin

  • Nitin Prasad

    Electrical and Computer Engineering, The University of Texas at Austin

  • Babak Fallahazad

    Univ of Texas, Austin, Electrical and Computer Engineering, The University of Texas at Austin

  • Kyounghwan Kim

    The University of Texas at Austin, Univ of Texas, Austin, Electrical and Computer Engineering, The University of Texas at Austin

  • Leonard Register

    The University of Texas at Austin, Electrical and Computer Engineering, The University of Texas at Austin

  • Emanuel Tutuc

    The University of Texas at Austin, Department of Electrical and Computer Engineering, The University of Texas at Austin, Univ of Texas, Austin, Electrical and Computer Engineering, The University of Texas at Austin